Constraining nuclear symmetry energy with the charge radii of mirror-pair nuclei

The nuclear charge radius plays a vital role in determining the equation of state of isospin asymmetric nuclear matter.Based on the correlation between the differences in charge radii of mirror-partner nuclei and the slope parameter(L)of symmetry energy at the nuclear saturation density,an analysis of the calibrated slope parameter L was performed in finite nuclei.In this study,relativistic and nonrelativistic energy density functionals were employed to constrain the nuclear symmetry energy through the available databases of the mirror-pair nuclei^(36)Ca–^(36)S,^(38)Ca–^(38)Ar,and ^(54)Ni–^(54)Fe.The deduced nuclear symmetry energy was located in the range 29.89–31.85 MeV,and L of the symmetry energy essentially covered the range 22.50–51.55 MeV at the saturation density.Moreover,the extracted L_(s) at the sensitivity density p_(s)=0.10 fm^(-3) was located in the interval range 30.52–39.76 MeV.

Predictions of nuclear charge radii based on the convolutional neural network

In this study, we developed a neural network that incorporates a fully connected layer with a convolutional layer to predict the nuclear charge radii based on the relationships between four local nuclear charge radii. The convolutional neural network(CNN) combines the isospin and pairing effects to describe the charge radii of nuclei with A ≥ 39 and Z ≥ 20. The developed neural network achieved a root mean square(RMS) deviation of 0.0195 fm for a dataset with 928 nuclei. Specifically, the CNN reproduced the trend of the inverted parabolic behavior and odd–even staggering observed in the calcium isotopic chain, demonstrating reliable predictive capability.

STARLIKENESS ASSOCIATED WITH THE SINE HYPERBOLIC FUNCTION

Let q_(λ)(z)=1+λsinh(ζ),0<λ<1/sinh(1)be a non-vanishing analytic function in the open unit disk.We introduce a subclass S^(*)(q_(λ))of starlike functions which contains the functions f such that zf'/f is subordinated by q_(λ).We establish inclusion and radii results for the class S^(*)(q_(λ))for several known classes of starlike functions.Furthermore,we obtain sharp coefficient bounds and sharp Hankel determinants of order two for the class S^(*)(q_(λ)).We also find a sharp bound for the third Hankel determinant for the caseλ=1/2.

Crystal Radii and Their Application on the Study of Electronic Structures of LaX(X=N,P,As,Sb)

以Ｐｈｉｌｉｐｓ－ＶａｎＶｅｃｈｔｅｎ理论和晶体光学性质为基础，计算了ＬａＸ（Ｘ＝Ｎ，Ｐ，Ａｓ，Ｓｂ）晶体的离子半径（单位：ｎｍ）：（Ｌａ：Ｎ）为（０．１４１４，０．１２３６），（Ｌａ：Ｐ）为（０．１５１８，０．１４８９），（Ｌａ：Ａｓ）为（０．１５３６，０．１５２６），（Ｌａ：Ｓｂ）为（０．１５８６，０．１６５１）．用ＬＭＴＯ－ＡＳＡ方法对ＬａＸ系列晶体的能带结构进行了计算．所得到的能隙是：ＬａＮ为２．３０ｅＶ，ＬａＰ为２．０５ｅＶ，ＬａＡｓ为１．６６ｅＶ，ＬａＳｂ为１．３４ｅＶ．与实验结果相符．这也证明了作者得到的半径的合理性．

Solution of the Nucleon Structure Problem from a Field Theory of Fermions and Bosons and the Origin of the Proton Stability

A bound state formalism derived from a fermion-boson symmetric Lagrangian has been used to calculate the nucleon masses, the charge neutrality of the neutron, the magnetic moments and the electromagnetic form factor ratios μpGEp/GMpand μnGEn/GMn. A quantitative description is obtained, assuming a mixing of a scalar bound state of 3(f f¯)fstructure with its corresponding vector (f f¯)fstate (f indicating massless elementary fermions). Only a few parameters are needed, mainly fixed by energy and momentum conservation. The nucleon stability is explained by an extra binding in the confinement potential, negative for electric and positive for magnetic binding of the proton, and opposite for the neutron. The stronger electric extra binding of the proton allows a decay of the neutron to proton and electron.

变基圆涡旋式压缩机多刚柔耦合动力学特性分析

为阐明汽车空调涡旋压缩机转子系统摩擦副非稳态动态激励机理,建立变基圆涡旋式压缩机多刚柔耦合动力学模型,以变基圆涡旋压缩机气体力为边界条件,研究轴系摩擦副动态接触激励;而后,基于变基圆涡旋式压缩机多刚柔耦合动力学模型,对动态接触激励进行影响因素分析。结果表明,动态接触激励力的频率响应峰值主要出现在100Hz、200Hz、700Hz与2300Hz及其边频处,为转频的整数倍次与动涡盘的1/2倍频处;为降低变基圆涡旋式压缩机轴系摩擦损耗,应合理设置防自转机构间隙及个数。

Analytical solutions for characteristic radii of circular roadway surrounding rock plastic zone and their application

In the non-uniform stress field, the surrounding rock plastic zone of the circular roadway shows different shapes under the different confining pressure conditions. Based on the boundary shape characteristics of the plastic zone, the characteristic radii of the plastic zone were proposed, namely the horizontal,longitudinal and medial axis radii, which could reflect the plastic zone shapes characteristics and classify the sizes of the key parts. On the theoretical basis of elastic-plastic mechanics, analytical solutions for the characteristic radii were obtained by theoretical deduction, and the relationships between the characteristic radii and key influencing factors were analyzed. Finally, the evaluation criterion of the circular roadway surrounding rock plastic zone shapes, evaluation criterion of the location of potential hazards caused by the roadway surrounding rock and evaluation critical points of roadway dynamic disasters based on characteristic radii were proposed. This work could provide a theoretical basis for stability analysis of the surrounding rock, support design, and guide the prevention and control of dynamic roadway disasters.

Polymer Radii and Moments in the Polycondensation Reaction of A_a Type

For the polycondensation reaction of A. type, the kth radius for k>2 can be expressed in terms of polymer moments.

Representations of Real and Complex Stability Radii of 2-Dimensional LinearSystems

Rigorous proofs are given for the representations of real and complex stability' radii of 2-dimensional linear systems. This representations can be used to analyze the robustness of a nominal 2-dimensional linear system under pelturbation of the system parameters, in particular testing the effect of numerical algorithms which are used to calculate the real stability radii of higher dimensional piecewise-linear systems.

Nuclear Interaction Radii for Light Exotic Nuclei

We developed a simple model to calculate the interaction radii for light neutron-rich nuclei based on Coulomb-modified Glauber model.Considering a relation of surface diffuseness of neutron distribution with the neutron separation energy of nucleus,the large increasing of nuclear interaction radii for exotic nuclei(such as ^(6)He,^(8)He,^(11)Li,^(11)Be)on ^(12)C target can be reasonably explained.

Magnetic Moments and Electromagnetic Radii of Nucleon and △（1232） in an Extended Goldstone-Boson-Exchange Model

We derive the exchange currents of pseudoscalar, vector, and scalar mesons from Feynman diagrams, and use them to calculate the magnetic form factors of nucleon and △(1232). The magnetic moments and electromagnetic radii are obtained by using those form factors and the parameters determined from the masses of nucleon and △(1232).We find the magnetic moments and electromagnetic radii of nucleon and △(1232) can be produced very well in the extended Goldstone-Boson-exchange model in which all of pseudoscalar, vector, and scalar meson nonet are included.The magnetic moments of △(1232) are closer to experiment values and results from lattice calculation than the results obtained by the model without other mesons except for pion and sigma.

Semi-Empirical Formulas for Nuclear Charge Radii

Considering the relationship between the nuclear radius and the average bindingenergy of nucleons,a simple semi-empirical formula for the nuclear rms charge radii is suggest-ed together with the formula for light neutron-rich nuclear rms neutron radii.These formulascan well fit the new experimental values.

两异径湿球颗粒间静态液桥力的近似解析公式及数值评测

针对异径球形湿颗粒间液桥力,以Young-Laplace公式为基础,结合环形近似法并引入等效半径,在宽松设定的条件下推导出了简化的近似解析公式。此公式形式简洁,且当两球半径相等时,可回归到Pitois等提出的径球液桥力公式。本文对此近似解析公式进行参数敏感度分析,发现随着颗粒间距的增大,液桥力对颗粒半径的敏感度降低。此外,本文近似解析公式与其他实验和理论结果进行对比发现,该近似解析公式与上述实验和数值结果相当吻合,表明该近似解析公式可以较准确地计算接触角较小时的异径球颗粒间的液桥力,因而适于湿颗粒系统的数值模拟。

基于变径基圆渐开线涡旋压缩机的几何模型及优化研究

针对现有变径基圆涡旋压缩机几何模型的定量分析及优化研究不够完善的问题,给出了变径基圆涡旋压缩机从吸气过程开始直到排气过程结束的完整工作腔容积变化规律.比较了格林定理法、图解法及法向等距法的容积计算差异性,分析了产生计算误差的原因,验证了几何模型的正确性.推导了齿面积利用率的计算公式,构建了行程容积及齿面积利用率的灵敏度模型,得出基圆半径变化系数及内侧型线发生角的影响尤为显著的结论.建立了一种考虑非线性约束且以行程容积与齿面积利用率为优化目标的多目标优化分析模型.结果表明:多目标遗传算法(NSGA-II)比多目标粒子群(MOPSO)算法综合性能更佳,且相较于优化前,某款汽车空调用变径基圆涡旋压缩机的行程容积提升了6.5%,齿面积利用率降低了4.27%.该研究能为变径基圆涡旋压缩机的优化设计及定量研究提供进一步的理论参考.

基于热带气旋风圈半径的海上风电场灾害预警时间估计方法研究及应用

利用2001—2019年美国国家海洋和大气管理局(NOAA)的热带气旋最佳路径数据集,统计分析了西北太平洋上影响我国沿海的热带气旋的移速、强度和风圈半径等气候特征。结果表明:8级、10级和12级热带气旋风圈半径的平均值分别为198.2 km、111.6 km、70.6 km,且风圈呈现不对称性,东北象限风圈半径最大,西南象限最小;风圈半径与强度变化呈现正相关关系;热带气旋移速、强度和风圈半径在各海域的空间分布特征明显不同,且8级和12级风圈半径随纬度变化存在显著差异。在气候特征分析的基础上,基于风圈半径、移速、强度和离岸距离等变量,提出一种针对海上风电场的热带气旋灾害预警时间估算方法,并根据不同风圈半径给出其预警时间的空间分布特征,为有效利用海上风能和开展抗台风措施提供参考。

基于ASCAT风场数据的热带气旋风圈半径的研究

研究介绍了一种基于ASCAT散射计风场数据计算热带气旋风速达到34节和50节时风圈半径(R34和R50)大小的方法,根据美国国家海洋和大气管理局提供的最佳路径数据,分析了2013—2022年发生在西北太平洋和北大西洋的热带气旋(TC)。结果表明:ASCAT估算的R34比最佳路径记录大4.5%左右,标准误差、均方根误差和相关系数分别为8.6 km、52.4 km和0.88;R50比最佳路径记录小约4.0%,标准误差、均方根误差和相关系数分别为-15.4 km、39.6 km和0.74,说明本方法能够较好地估计TC风圈半径。两个海盆中TC强度(最大持续风速)与R34的相关性较强(相关系数为0.62~0.66),比R50(与TC强度的相关系数为0.36~0.48)能够更好地表征TC的影响强度和尺度大小,也说明了从ASCAT风场得到的风半径信息对于监测和预报TC强度是有参考价值的。用R34定义TC大小和分类统计,发现两个海盆上平均尺度的峰值出现在9月和10月,中型TC的总数量最多,3种类型TC的变化趋势总体均呈现单峰分布,小型和中型TC的峰值出现在9月,大型TC的峰值滞后1个月。

秦岭火地塘林区土壤大孔隙分布特征及对导水性能的影响

大孔隙广泛分布于森林土壤中,是定量研究与土壤水分运动有关的重要因素,其研究可深化森林涵养水源机理的认识。基于田间持水量到饱和含水量之间的土壤孔隙作为大孔隙的标准,利用土壤水分穿透曲线和Poiseulle方程研究了秦岭火地塘林区森林土壤大孔隙分布特征及其对土壤饱和导水率的影响。结果表明,林区土壤大孔隙当量孔径主要分布在0.3—3.8 mm之间;当量孔径>1.5 mm的大孔隙密度较小,其数量仅占大孔隙总数量的5.37%;各当量孔径的大孔隙密度随土层分布基本呈现为上层大、下层小的特点,且垂直分布差异显著,其与有机质含量分布有极显著的相关性。0—60 cm土层大孔隙平均面积比顺序为:针阔混交林>油松林>落叶阔叶林>华山松林。不同当量孔径的大孔隙密度与饱和导水率呈显著正相关关系,当量孔径大于1.5 mm的大孔隙密度决定了饱和导水率84%的变异;大孔隙率平均在1.6%—13.3%之间,当其小于5%时,饱和导水率随着大孔隙率增大而增大。

晶体中原子的平均范德华半径

根据晶体中原子的平均体积数据提出包括全部金属元素的原子平均范德华半径值。与现有几个重要的范德华半径体系进行了初步的比较,指出范德华半径值在应用中值得注意的问题,简要提出了有关范德华半径今后研究的方向。

应用MODIS数据对新疆北部大雾地面能见度和微物理参数的反演

大雾区域地面能见度、垂直总水汽含量、雾滴有效半径等因子是对大雾进行有效监测的重要参数。以MOD IS探测器的卫星遥感数据资料为主要数据源,定量反演了这些大雾参数。能见度参数反演结果和气象地面观测能见度信息数据的对比表明其效果良好。所得垂直总水汽含量、雾滴有效半径也与以前国内外相关多年研究的结果趋势一致。此方法在这里成功的应用,说明其在遥感大雾监测中的潜在应用价值。

一次暴雨过程中云微物理特征的卫星反演分析

利用卫星反演技术和云微物理分析方法,以陕北2006年7月2日发生的暴雨过程为例,反演了云顶粒子有效半径(R_e)、云顶温度(T)等云物理特征参数,通过卫星不同时次对暴雨云团的探测资料,分析了暴雨发展过程。暴雨云团表现为多单体特征,发展旺盛期对流单体的数量明显增加、云团尺度大幅增加。根据暴雨云系中的对流云、层云、过冷水云、低云(未被高云遮挡住)4种类型,分别选择了9个代表区,用于分析这次暴雨过程中不同类型云的物理特征和垂直结构。结果表明:此次暴雨云团由多种高度的云组成,低云高度较低,温度较高,云顶在0—-10℃;层云高度略高,T为-10—-20℃,R_e为10—20μm,并含有连片分布的过冷水云(R_e为10μm左右);高度最高的云为对流云,镶嵌在系统性层云中或在其上发展,T最低达到-80℃左右。从云底至0℃层存在一个较厚的凝结增长带,R_e为5—10μm;0—-10℃层存在一个碰并增长带,R_e从13—15μm增长到20—25μm,但其厚度小于凝结增长带;T<-10℃层以上存在一个深厚的冰相增长带,表明在对流云团的发展成熟期,冰相增长过程为优势云物理过程。随着云的逐渐发展,混合相增长带由厚变薄,冰化增长带增厚,晶化温度升高、高度降低,表明在对流云团发展到成熟的过程中,冰化增长带在下传,云中冰化增长过程向下传递明显。